It isn’t too often that the culture shifts seismically right before our eyes, but that’s exactly what happened on Dec. 10 during the latest in the reality TV series a.k.a. the GOP debates.

Because everyone knows that cheating on your wife is far more important than, say, global warming, the good folks at ABC decided to devote precious time to the question of marriage or what I now think of as The Fidelity Test. They were, as Ron Paul would say about Newt Gingrich, “stirring up trouble.” Governor Rick Perry argued that marital fidelity should be a determining factor in voter’s minds: “If you cheat on your wife, you’ll cheat on your business partner.” Sorry, but that dog won’t hunt.

Then came Senator Rick Santorum, who bested all the candidates with seven children from his 21-year marriage, though Romney tried to compete by lumping children with grandchildren: “I have quite a few of them, 16.” Ron Paul, in his charming way, won points for valiantly changing the subject. “What about our oath of office? That’s what really gets to me!”

All of it was, of course, a build-up to Gingrich, whose marriage history looks like the grand finale of a fireworks display, complete with sparklers, black snakes and Roman candles. But if anyone thought Gingrich would go up in flames over this character test, they were sorely disappointed. Gingrich poured cold, quenching water on the question, and as I watched it fizzle, I thought, good riddance to the Fidelity Test.

Granting that people have “the right to ask every single question” and “render judgment,” Gingrich went on to hit the key notes in the redemption narrative Americans hold so dear: admit to mistakes, go to God for forgiveness, seek reconciliation. End of story — oh, plus, “I’m a 68-year-old grandfather,” said Gingrich, wrapping up with a cuddly image. It worked. (Before you throw the Cain Flame-out at me, let me add that Gingrich did not undergo his act of redemption during this round of GOP company time.)

Romney will continue to poke at the burning embers, trying to reignite the issue. His ads, and the appearance of his wife on the trail, are meant to set himself up as the “constant” one, a foil to Gingrich’s foibles. But it’s too late.

Santorum brought up again his intention to “promote the institution of marriage” and began to lecture the audience about the damage of its breakdown. “That’s the most important luxury,” he said, “is a mom and a dad.” Apart from the obvious, that a mom and a dad are, in the first place, hardly a luxury but a necessity in begetting children, the sanctimony rankled. After all, too many American marriages have hit the shoals; too many Americans have gone through the pain of divorce — for good reasons — and too many people have done their best to raise well-adjusted children in spite of the rupture.

Most of us don’t take on the suffering of divorce lightly. It is difficult, humiliating, sad death to go through, and the mourning of a marriage, no matter what the circumstances of its passing, takes a while. Gingrich, so well-liked by the very social conservatives who care the most about this subject, is actually giving all failed marriages a pass on his coattails. It’s an unusual but welcome development: a politically-motivated cultural evolution. None of us believe that the failure of a marriage does irreparable damage to our moral fiber or to our children — much less our country.